By Dominic Raab MP (Esher and Walton), who was a British diplomat between 2000 and 2006.

War hero, or war criminal? That was the debate I inherited early in 2006, returning from a posting as head of war crimes at the British Embassy in The Hague, to take on the ‘Near East’ portfolio in London. Israeli General, Doron Almog, had narrowly escaped arrest at Heathrow pursuant to a private prosecution brought by Palestinian activists. A hero to Israelis – in 1976, Almog was amongst the crack troops that rescued Israeli citizens hijacked by Palestinian terrorists and held in Entebbe. A war criminal to Palestinians – who accused him, as Commander in the Gaza strip, of demolishing homes (Israelis say the buildings were hideouts for terrorists).

Most of the cases I worked on in The Hague had been more clear-cut – like the Srebrenica massacre of 7,000 Muslim men and boys in Bosnia, or the horrific attacks on children in the long forgotten conflict in northern Uganda. International consensus in favour of criminal prosecutions had been slowly but surely built up around the moral clarity and widespread outrage that followed such wanton violence targeted against innocent civilians. Even the Bush administration – deeply sceptical about the International Criminal Court – gave tacit backing to its pursuit of those responsible for the appalling crimes in Darfur.

But, an increasing number of countries – including Britain – are also taking national jurisdiction over such international crimes. International tribunals are expensive, cumbersome and bureaucratic. Domestic courts, some argued, should plug the gaps.

In the UK, it came with a twist. Our justice system allows for ‘private prosecutions’ – pro-active citizens can bring criminal culprits to book, where the state fails to act. Today, they are relatively rare and – like the prosecution brought by the family of murdered London teenager Stephen Lawrence in 1995 – they often fail. The Crown Prosecution Service would normally take over strong cases. Still, the principle remains, although it was not designed to deal with crimes committed abroad. The procedure allows private individuals to seek an arrest warrant from a magistrate’s court, which applies a wafer thin test. Does jurisdiction exist? And is there any information that might support the allegations? No real evidential threshold. No requirement that a prosecutor check the credibility of the claims.

The government now plans to change those rules in war crimes cases. That may be controversial – but it is the right decision.

It may not matter much in relation to allegations of theft or assault in this country. A court can set bail, designed to secure justice without turning the defendant’s life upside down unless and until he is convicted. But, if the arrest warrant is issued against a foreign government minister, military commander or official, the implications are explosive. The accused cannot leave the country, throwing his life into turmoil – not to mention the diplomatic row that will invariably follow. Fine if we are dealing with a fugitive like Ratko Mladic, the Bosnian Serb commander wanted for Srebrenica, against whom there is now a mass of evidence. But, in this country, the arrest warrant can be issued on the flimsiest of evidence – and that makes it vulnerable to abuse.

Attention-seeking lawyers and campaign groups have cottoned on. The Palestinian Center for Human Rights, the group that pursued General Almog, is not especially radical. But, it has a political agenda – it opposes the Oslo accords forged between Yitzak Rabin and Yasser Arafat, and defends the militant group Hizb Ut Tahrir. The real prize for such groups is less a criminal conviction – and more the controversy and media limelight that any high profile arrest would bring.

The arrest warrant obtained last year by another Palestinian group, against Tzipi Livni, was tenuous at best. It made a series of allegations about her responsibility, as Foreign Minister, deriving from military operations against Hamas in Gaza. Leaving aside the low burden of evidence needed for an arrest warrant, as Foreign Minister, Livni would not have had either direct or ultimate ‘command responsibility’ anyway. The real reason for targeting her was that – at the time the warrant was sought – she was no longer a minister, capable of claiming any sort of immunity. That made her a much easier target.

As things stand, individuals or groups can use the wide scope of our law to secure an arrest warrant for spurious allegations or claims based on scant evidence. That risks injustice for those targeted, and disruption to Britain’s international relations. None of this helps to resolve the Israeli-Palestinian conflict – which needs urgent attention, to spare further life lost on both sides. But, it may just tempt other governments to follow the British example. What is to stop other countries passing similar laws, and political groups seeking arrest warrants against British commanders who have served in Iraq or Afghanistan? Britain should take care as to the precedent she is setting.

The answer is not to weaken accountability under national or international law for war crimes. But, we could raise the burden of evidence needed in the UK to obtain an arrest warrant in such cases – or, better still, require a senior prosecutor to check the claims first, as a safeguard against abuse. That is the option the Justice Secretary announced yesterday – proposing legislation to require that the Director of Public Prosecutions approve an arrest warrant.

It is the right decision – and not just for diplomatic reasons. It is difficult enough holding war criminals to account, given the immense challenges of collecting evidence and arresting fugitives. But, an international consensus is growing that there are certain crimes, like the deliberate targeting of innocent civilians, that must be held to account. The surest way to undermine that fragile consensus is to allow the criminal process – in this country or abroad – to be abused for political purposes.